Janus: The Gatekeeper

[Piet] wrote in to tell us about his hack that allows for his front gate to be opened without a key. Unlike this hack that we featured in August, you don’t need a subway pass, just a good memory. As explained in his article (and the video after the break) if the proper sequence of doorbell rings is input, the gate unlocks itself.

For hardware a [mehduino] is used to take the doorbell input and decide whether or not the “secret knock” has been achieved. The door can be unlocked remotely via a button on the processor. Reprogramming the code is achieved by simply holding the program button while the code is entered on the “remote ringer” button.

Be sure to check out the video after the break to see this lock in action. The housing application may not be exactly what you expect. Also of interest, is that in true hacker fashion, the bare processor is hanging by a hook on his wall!

It is very insecure indeed, but as you can see in the video it is very easy to bypass the gate anyway. Downstairs there are locked doors. So for this application it is secure enough. I would however not advise to use this on an actual front door.

Yea I was going to say that, that gate is about as secure as a beaded curtain! Nice hack though, you could apply this on a home doorbell by using the ring code to announce who’s at the door, give each friend their code and when they come over you know who to let in and who to blow off. :)

Since it does not require any wires, it is especially valuable to
people who live in leased homes and apartments.
This USB kit is good for people who need to monitor what’s going
on in their office at home or at work. Make sure your kids know the
rules about what to do when the doorbell rings.